Torque-transmitting apparatus

ABSTRACT

A torque-transmitting apparatus for motor vehicles includes a hydrokinetic torque converter with a housing connected to the driving shaft of an engine. The housing contains a pump and a turbine, the latter arranged to drive an input shaft of a power train. At least one damper is arranged in the power flow path between the turbine and a rotary output element of the apparatus. The damper has an input member constrained to rotate with the turbine and an output member connected to the rotary output element. The input member and the output member are rotatable relative to each other against the opposing forces of energy-storing devices arranged between the input member and the output member. The input member has a radially outer portion in form-locking engagement with the turbine.

This application is a division of co-pending application Ser. No.09/805,697, filed Mar. 13, 2001, which is a division of application Ser.No. 09/305,504 (now U.S. Pat. No. 6,244,401), filed on May 5, 1999. Eachof these prior applications is hereby incorporated herein by reference,in its entirety.

BACKGROUND OF THE INVENTION

The invention relates to a torque-transmitting apparatus with afluid-operated torque coupler such as, e.g., a fluid coupling or ahydrodynamic torque converter, with at least one housing that can beconnected to a driving shaft of a prime mover. The housing contains atleast one impeller pump receiving torque from the housing and a turbinethat is connected to the input shaft, such as a transmission shaft, of apower train to be driven. Also, if applicable, the housing contains atleast one stator arranged between the pump and the turbine. Further, atleast one damper is arranged in the power flow between the turbine and arotary output element of the device. The damper has an input memberconstrained to rotate together with the turbine and an output memberconnected to the rotary output element. The input member and the outputmember are rotatable relative to each other at least against theopposition of a restoring force furnished by energy-storing devicesarranged between them.

Torque-transmitting apparatuses of this kind have been proposed, e.g.,in DE-OS 195 14 411. To allow rotational displacement of the input andoutput members relative to each other, it is customary fortorque-transmitting apparatuses of this kind to be equipped with a hubthat has a toothed internal profile establishing a positive engagementwith the transmission shaft and also a toothed external profile whichmates with a further component, normally a further hub that carries theturbine and has a toothed internal profile, with play between the flanksof the mating teeth. When a lockup clutch is added that is activated byan axial control piston, there needs to be a corresponding axial spaceto allow for the axial travel of the hub containing the two toothedprofiles. The manufacture of hubs of this kind is complex and thereforeexpensive. Furthermore, due to the required axial dimension, longertransmission shafts will be needed. Added to this is the difficulty ofconnecting bulky hub components with the filigreed construction of theturbine shell. Also, dampers that extend far in the radial directionhave a tendency to wobble. If in an attempt to solve these problems, thedamper is axially docked to the turbine along two or more perimeters ofdifferent radii, this will cause undesirable stresses and frictionallosses in the damper.

OBJECTS OF THE INVENTION

It is therefore an object of the present invention to improve the designof a torque-transmitting apparatus in a manner that allows a stress-freeaccommodation of the damper as well as economical and technicalimprovements in the manufacturing process for torque-transmittingapparatuses of this kind. According to a further object of theinvention, the device is to be manufacturable in such a manner that amodular assembly without time-consuming fastening operations can beperformed during final assembly. Also required of thetorque-transmitting apparatus are the capabilities to transfer torque ofhigh magnitude and to attenuate rotational perturbations over a broadRPM range. Besides, the unit is to meet the objectives that it willminimize wear and prolong the useful life of the overall system of whichit is a part.

SUMMARY OF THE INVENTION

The invention is embodied in a torque-transmitting apparatus of the kindthat has a fluid-operated torque coupler such as a hydrodynamic torqueconverter or a similar device comprising

at least one housing that can be connected to a driving shaft of a primemover,

at least one pump that is arranged inside of and driven by the housing,

a turbine that is connected to and drives the input shaft of a powertrain such as a transmission shaft and also, if applicable,

at least one stator arranged between the pump and the turbine, andfurther

at least one damper arranged in the torque-flow path between the turbineand a rotary output element of the apparatus, with an input member ofthe damper being constrained to rotate together with the turbine and anoutput member of the damper being connected to the rotary outputelement, the input member and the output member being at least rotatablerelative to each other at least against the opposition of the restoringforce exerted by energy-storing devices arranged between them.

In accordance with one presently preferred embodiment of the improvedtorque-transmitting apparatus, the damper at its outside perimeter isdirectly or indirectly connected to the turbine through a positiverotational constraint. This connection may be free of play relative tocoaxial rotational displacements but may allow an axial displacement ofthe turbine and the input member of the damper relative to each other.For example, the connection may be axially displaceable by means of anaxial plug-in connection with the damper rigidly attached to a hub. Theproblem can further be solved through a torque-transmitting apparatuswith a damper whose connection to the turbine shell or turbine, or tothe hub, is rotationally fixed both along an inside and outsideperimeter, while in the axial direction the connection is fixed onlyalong one perimeter, either on the hub or on the turbine shell, so thataxial stresses are relieved by an axial displacement at the axiallynon-restrained connection.

In accordance with a further inventive concept, there may also be anaxially and rotationally fixed connection at the outside perimeter ofthe damper in which case, in order to prevent stresses in the damper,the inside perimeter of the damper may be designed to be axiallydisplaceable, e.g., in an arrangement where the damper, by means of apositive circumferential coupling such as a toothed profile, engages acomplementary profile on the hub. In addition, the profile on the hubmay be axially fixed but rotatable on a complementary profile of theturbine hub on which the turbine is seated, with the amount ofrotational play designed to be at least equal to the working range,i.e., the effective angular range, of the damper. The play in theform-fitting engagement between the turbine hub and the hub may also beobtained through additional devices such as window-like openings thatare distributed over the circumference of the hub and are engaged withangular play by a corresponding series of axially directed projectionson the turbine hub.

With particular advantage, the connection between the turbine and theinput member of the damper is accomplished through welding processessuch as laser welding, impulse welding, or resistance welding, in whichcase the damper can be centered on the hub by means of a disk-shapedpart that holds the energy-storing devices, or on the turbine shell,e.g., by providing the turbine shell with a series of projections thatare distributed over the circumference and that may also serve aslocating references for the weld.

It is advantageous for the torque-transmitting apparatus to be providedwith a lockup clutch arranged in the torque-flow path between thedriving shaft and the damper, in which case it has proved to bebeneficial if the lockup clutch, by means of friction linings or laminardisks, establishes a positive engagement with a housing surface andtransfers the torque to be transmitted directly to the input member ofthe damper. Thus, when the lockup clutch is engaged, the torqueconverter is bypassed and the torque to be transmitted is introduceddirectly into the damper and from there to the rotary output element andsubsequently to the transmission shaft. When the lockup clutch isdisengaged, the turbine will impart the torque that has beenconverted—in most cases amplified through the effect of the stator—tothe input member of the damper from where the torque will follow thesame path as has been previously described.

The clutch can be engaged and disengaged through an axially moveablecontrol piston that is controlled by an application of pressure. It isadvantageous if the control piston defines a plenum chamber which, inthe engaged state of the lockup clutch, is essentially sealed tightagainst the interior space of the housing (except for insignificantflows of pressure medium into the housing that may be provided to coolthe friction linings) and is energized by a pressure medium identical tothe converter fluid that is admitted through a bore hole, whereby apressure force is applied to the piston in the axial direction towardsthe turbine. According to the invention, this axial displacement iscompensated by allowing an axial displacement of the axial plug-inconnection. Another possibility for controlling the piston is to applyan over pressure to the control piston, in which case the piston willseal off the chamber when the clutch is open; and when the pressure inthe chamber is reduced, the piston is pushed to the housing wall by thefluid pressure in the torque converter, thereby causing the lockupclutch to engage.

The control piston can be centered on the transmission shaft, on a hubholding the housing of the torque converter, or on another appropriatepart of the apparatus and is preferably provided with sealing means atthe interface surfaces to these components for the purpose of sealingthe plenum chamber in the same manner as the piston can be sealed at itsoutside perimeter against the housing.

A further embodiment comprises a form-fitting engagement between thecontrol piston and the housing by means of complementary profilesextending in the axial direction, in which case the axial profile isformed by alternating ridges and grooves in the shape of ring segmentsthat are distributed over a perimeter where, e.g., the ridges of thecontrol piston may engage the grooves in the housing. An advantage ofsuch configuration is the direct engagement of the piston with thehousing so that the piston can transmit torque to the friction liningsdirectly and/or through other pressure-transmitting devices, whereby theuse of an enlarged friction surface and/or of a larger number offriction surfaces and thus a greater transmission torque is madepossible.

For this purpose, there may be one or more carriers of friction liningsin the form of annular disks or laminar disks that can carry frictionlinings in the outer zones of their axially facing surfaces. Thefriction-lining carriers or laminar disks are axially movable, and thepressure force is applied against a ring-shaped pressure plate that isconnected with the housing either directly or indirectly, e.g., welded,riveted or attached to a flange that is, in turn, connected to thehousing. For better cooling fluid distribution, the pressure plate canhave one or more circles of holes.

It is advantageous to center the friction-lining carrier on the housing.For this purpose, the friction-lining carrier can be provided with lugsthat protrude axially towards the housing and are inserted in a shoulderextending in the direction away from the friction-lining carrier.

A further advantageous embodiment renders it possible to configure thepiston itself as the lockup clutch or, more precisely, as thefriction-lining carrier. For this, the radially outer part of thecontrol piston surface that faces axially towards the housing carries aring-shaped friction lining that may be provided with an optimizedsurface finish to achieve better cooling. The piston surface may be bentin the axial direction towards the turbine, so that the piston may restin form-fitting contact against the housing, which in the respectivesurface portion is shaped similar to a cone shell.

As already described above, the lockup clutch is connected through oneof its components to the input member of the damper. In one embodiment,the connecting part may be the control piston itself in the mannerdescribed above, in which case the piston may be connected to lateralparts of the input member by rivets, weld joints or similar means. Afurther embodiment employs a ring-shaped friction-lining carrier thatmay form an axial plug-in connection by virtue of an appropriatelyshaped lateral portion. In this case the friction-lining carrier has aform-fitting engagement with the input member of the damper, e.g., bymeans of internal teeth at its inside perimeter and, e.g., an axiallyoriented profile on the lateral part of the input member. The advantagesof axial plug-in connections in accordance with the invention are thatthey compensate for axial displacements and facilitate the manufacturingprocess by virtue of a modular configuration, because systems of thiskind can be built by plug-in assembly without further resort tofastening undertakings such as, e.g., welding or riveting, thus allowingthe use of work stations that are not equipped with the respectiveinfrastructure.

Further advantageous embodiments of axial plug-in connections betweencomponents of the damper and components of the turbine will be describedhereinafter. An advantageous configuration has two components of the twounits to be connected meeting each other approximately at a right angle,i.e., in the form of a radially and an axially extending flange,respectively, with the two parts in a form-fitting engagement. In this,it may be advantageous to provide the radially extending flange withexternal teeth and the axially extending flange with axially orientedteeth.

It may also be advantageous if a radially extending flange-like part hasclosed cutouts, distributed along a circle of smaller radius than theoutside perimeter, that are engaged by axially directed extremities ofthe axially extending flange-like part.

A preferred embodiment may be a radially oriented flange-like part that,starting at its inside perimeter, follows the shape of the turbine shelloutwards in the radial direction and is attached in this portion, e.g.,welded or riveted. From there, the flange-like part bends into theradial direction and has a toothed profile along its exteriorcircumference that is engaged by the lateral part of the input member ofthe damper. For this purpose, the lateral part at its exteriorcircumference bends into the axial direction and forms the axiallydirected flange-like part that carries, e.g., the axially orientedtoothed profile.

A further advantageous embodiment may include a flange-like part in theshape of an annular disk that adjoins along its inside perimeter theturbine shell and conforms to the shape of the turbine shell towards theinside in the radial direction, is attached in the shape-conformingportion as described above and then curves into the axial direction. Theprofile facing away from the turbine shell in axial direction, e.g., atoothed profile, engages in closed recesses distributed over thecircumference of a radially directed lateral part and in this mannerforms an axial plug-in connection. To form this plug-in connection, itmay be necessary for the axially directed toothed profile to passthrough the output member before engaging the input member of thedamper, given that the output member is interposed axially between theturbine and the input member. For this purpose, the output member has acircular arrangement of elongated holes matching the number of teeth.The angular width of the holes corresponds to the maximum angulardisplacement of the input and output members relative to each other sothat at the same time the elongated holes in combination with theaxially directed teeth of the axially oriented flange-like part that isconnected to the turbine form at least one stop for the angulardisplacement of the damper.

In an advantageous arrangement, the axially extending flange-like partcan itself be in the form of a hub that carries the turbine, the latterbeing connected to the hub by, e.g., welding or riveting. The hubcarrying the turbine, in turn, can be seated on a further hub thatperforms the function of the rotary output element and is attached tothe transmission shaft. The axially extending flange-like part has aprofile established, e.g., by axially oriented teeth that extend intoenclosed cutouts corresponding to the number of teeth in the flangewhereby an axial plug-in connection is formed. Depending on theconfiguration of the damper, it may be necessary with this embodiment,too (as described above), to provide in the output member an appropriatearrangement of elongated holes which, in combination with the axiallydirected profile of the axially oriented flange for the axial plug-inconnection, can function as stops for the relative displacement betweenthe input and output members of the damper. The output member, being aradial extension of the hub that is attached to the transmission shaft,may also be configured as a separate flange-like part, in which case theflange needs to be centered on the hub and attached through arotationally fixed connection.

It can further be advantageous if an annular disk in the form of aradially extending flange-like part with an exterior profile, e.g., anarrangement of external teeth, is centered on the hub that carries theturbine. By attachment means such as, e.g., rivets, the annular disk isrotationally tied to the turbine, and its outward-pointing teeth,mentioned above by way of an example, engage a lateral part that is bentin the axial direction along the interior perimeter and (also by way ofexample) has a complementary, axially directed toothed profile. In thiscase, too, a connection is established that constrains rotational butallows translational displacement of the engaged parts relative to eachother. The angular displacement of the damper may advantageously bedefined by means of a toothed profile with play between the respectivetooth flanks of the hub and the annular disk. The outward-facing profileof the hub may also be engaged by the inward-facing profile of theoutput member, albeit without play at the flanks, in order to secure theoutput member for rotation with the hub. This has the advantage ofsaving space in the axial direction of the hub, given that the relativeaxial displacement occurring between the damper and the turbine as aresult of the axial movement of the control piston is alreadycompensated for by the axial plug-in connection.

The axial plug-in connection between the damper and the turbine indifferent practical variations may be arranged, e.g., at a radialdistance beyond the energy-storing devices, at an intermediate radiusbetween the storage devices in the case of at least two damper stages,or inside the radial distance of the storage devices.

Other embodiments of the invention concern the advantageous design ofthe damper. The damper may be of the single-stage or multi-stage type. Adual-stage damper may be configured in such a way that the damper stagescan function in a serial or parallel mode, with the additionalpossibility of different limits of rotation so that, e.g., in a serialarrangement of the damper stages the relative rotation of one stage isstopped before the other stage, e.g., for the purpose of achievingparticular damping characteristics.

In connection with the damper, it is also advantageous to combinedifferent energy-storing devices, e.g., by selecting arc-shaped springsin a radially exterior damper stage, and short, stiff spring elementsfor use in smaller-diameter areas so that, e.g., a damper characteristiccan be achieved that provides a high amount of energy to compensate forboth large-amplitude rotational irregularities at low RPM andsmall-amplitude rotational irregularities at high RPM. In this kind ofan arrangement, the arc-shaped springs in the radially exterior area maybe pre-bent to their working diameter and are retained radially by achamber that is formed by at least one lateral part or by othercomponents of the damper or of the torque-transmitting apparatus, e.g.,by the wall of the housing. In addition, there may be wear-reducingcomponents such as wear-protection shells interposed between thearc-shaped springs and the chamber, with the characteristic of thearc-shaped spring being determined by all of the aforementioned factors.

It can be advantageous to provide the individual damper stages withdisplacement properties that depend on the direction from which thetorque is introduced. Thus, the damper system may be designed tofunction in two stages in the “pull” mode and in one stage in the “push”mode. In this manner, the damper characteristic may be adapted to thepossibility of hard transient peaks in the torque-flow that areintroduced from the “push” side, i.e., from the input shaft of thetransmission, in which case, e.g., the soft damper stage is bypassedcompletely and the firm damper stage is effective instantly. The bypasscan be accomplished by means of limit stops that block angulardisplacement against the drive direction in the input and output membersof the damper stage that is inactive in the push mode.

It is advantageous to accommodate the storage devices in disk-shapedparts that have dimensionally matched recesses into which the storagedevices are fitted and which may at their ends have force-introductionelements facing against the direction of the restoring force. Theforce-introduction elements retain and thereby compress the storagedevices when the input and output members are displaced in relation toeach other. The disk-shaped parts forming the input and output membersmay be arranged in such a manner that either the input or output memberis formed by two mutually connected lateral parts, while the other ofthe two members is formed by a corresponding disk-shaped, flange-likepart arranged between the two lateral parts. A further embodiment thatbrings cost advantages has two disk-shaped parts, one representing alateral part serving as input member and the other representing alateral part serving as output member. In two-stage dampers, it canfurther be cost-effective to use a common disk-shaped part working withboth damper stages.

Further in the interest of optimizing cost, the disk-shaped parts maytake on additional functions. For example, as mentioned already, one ormore disk-shaped parts may form a chamber for the energy storingdevices, or they may contain the axial plug-in connection between thedamper and the turbine, and/or they may perform other functions.

It is further advantageous for cost-optimization if disk-shaped partsand different other components are made of one piece. Thus, e.g., theoutput member of the damper together with the rotary output element(e.g., the hub that is arranged on the transmission shaft), or theoutput member together with the hub that carries the turbine, may bemade of one piece.

An advantageous and cost-effective embodiment of means for limiting theextent of angular displacement avoids the need for special stops. Forthis purpose, a circular arrangement of elongated holes may be providedon at least one disk-shaped part, where the fasteners (e.g., rivets)that are in any case already provided pass through the holes and areheld on the opposite side by another disk-shaped part and/or by means ofa sheet metal holder. The angular width of the elongated holes ispreferably selected so that the extent of relative angular displacementbetween the input member and the output member is limited by the ends ofthe elongated holes stopping the shafts of the fasteners.

It is advantageous to provide displacement-limiting stops insofar as adamper or either some or all of the damper stages can be bypassed, sothat the damper or the damper stages can be protected from wear. Thismay apply particularly in the case of wear-prone versions with storagedevices that, e.g., contain arc-shaped springs, permit large angulardisplacements, and/or are exposed to strong shock loads. To guardagainst premature failure, it is advantageous if initially one damperstage is totally bypassed by means of displacement-limiting stops, whilethe second stage is either not bypassed at all or only at a later point.When a damper or a damper stage reaches its limit stop, the torque thatpreviously entered into the energy-storing device is transmitted throughthe stop directly to the output member of the bypassed damper or damperstage. It may also be advantageous to provide different angulardisplacement limits in the damper device and its damper stages dependingon the direction of the torque, i.e., whether the torque works in thepull or push direction, respectively. Thus, it may be advantageous, forexample, to provide limit stops in such a manner that a damper stage isentirely bypassed in the costing mode. Likewise, there may be advantagesto a configuration in which, e.g., one damper stage works only in thecoasting direction while the other stage works only in the pulldirection.

The novel features that are considered as characteristic of theinvention are set forth in particular in the appended claims. Theimproved apparatus itself, however, both as to its construction and itsmode of operation, together with additional features and advantagesthereof, will be best understood upon perusal of the following detaileddescription of certain presently preferred specific embodiments withreference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary sectional view of a novel torque-transmittingapparatus with a two-stage damper.

FIG. 2 is a fragmentary sectional view of a further embodiment of atorque-transmitting apparatus with an axial plug-in connection locatedat a radial position between the energy-storing devices of two damperstages.

FIG. 3 is a fragmentary sectional view of an embodiment of the inventionwith axially directed projections formed on the hub.

FIG. 4 is a partial view of a disk-shaped part of a damper.

FIG. 5 is a fragmentary sectional view of an embodiment of a damper.

FIG. 6 represents a fragmentary view of another embodiment of a damper.

FIG. 7 is a fragmentary axial sectional view of an embodiment of atorque-transmitting apparatus with a single-stage damper.

FIG. 8 is a fragmentary axial sectional view of an embodiment of atorque-transmitting apparatus with a two-stage damper and a two-parthub.

FIGS. 9-12 are fragmentary sectional views of further embodiments oftwo-part turbine dampers.

FIG. 13 represents an embodiment with a damper docked fixedly to theturbine shell.

FIG. 14 represents a modified version of the damper of the embodiment ofFIG. 13.

FIG. 15 represents a detail of an embodiment comprising a damper that isdocked fixedly to the turbine shell.

FIG. 16 represents an embodiment of a torque-transmitting apparatuscomprising a damper that is docked fixedly to the turbine shell.

FIG. 17 represents a hub of the embodiment of FIG. 16.

DETAILED DESCRIPTION OF THE INVENTION

The torque-transmitting apparatus 1 shown in FIG. 1 has a housing 2confining a torque converter 3. The housing 2 is connected to a drivingshaft that can constitute the output shaft of a prime mover such as,e.g., the crankshaft of a combustion engine. As is known, the housing 2is constrained to rotate with the shaft by a sheet metal disk that isconnected at an inner radius with the driving shaft and at an outerradius with the housing.

The housing 2 comprises a shell 4 adjoining the driving shaft or thecombustion engine and a further shell 5 axially distant from the drivingshaft and attached to the housing shell 4 by means of a weld 2 a. Thetwo housing shells 4 and 5 are connected and sealed at their radiallyouter portions by a welded connection 6. In the illustrated embodiment,the housing shell 5 simultaneously serves as the outer shell of the pump7. This is accomplished by connecting the vane portions 8 to the housingshell 5 in a manner known manner per se. A turbine 10 is interposedaxially between the pump 7 and the radially extending wall 9 of thehousing shell 4. A stator 11 is provided between the radially interiorportions of the pump 7 and the turbine 10.

Furthermore, the internal space 12 enclosed by the housing shells 4, 5contains a torque-elastic damper 13 that establishes torque-elasticconnection between the output hub 14 and a driving part. In theillustrated embodiment, the driving part is formed by the housing shell4 in the case where the lockup clutch 15 is engaged or operates withslip. When the lockup clutch 15 is disengaged or slipping, the drivingpart is formed by the turbine 10. The converter lockup clutch 15 isarranged in series with the damper 13.

The hub 14 representing the rotary output element of thetorque-transmitting apparatus 1 can be coupled through an interiortoothed profile 16 to an input shaft (not shown) of a transmission. Theturbine 10 is rotatable within a limited angular range relative to therotary output element, i.e., the hub 14, against the opposition of thedamper. In the case of a damper based on the principle of shear flow ofa hydraulic medium, while the relative rotation between the turbine 10and the output element 14 would still be damped, the angle of relativerotation would be unrestricted.

The output hub or rotary output element 14 is non-rotatably connected,e.g., welded or caulked, to the flange-like output member 17 of thetorque-elastic damper 13. The input member 18 of the torque-elasticdamper 13 is at its outer perimeter bent in the axial direction towardsthe turbine and forms an axially oriented flange-like part 19 with a rimof axially directed teeth 20. At its interior perimeter the input member18 is bent in the axial direction towards the housing shell 4 and has arim of axially directed teeth 21 so that the input member 18 transmitsthe torque flow through form-locking connections to the lockup clutch 13and the turbine 10 by means of the toothed rims 20, 21. For thispurpose, a radially oriented flange-like part 22 is attached to theturbine 10 by a weld 24 along its inner perimeter to the outside of theturbine shell 23. The flange-like part 22 along its outside perimeterhas a toothed rim 26 and thereby forms an axial plug-in connection 78 tothe input member 18 of the damper 13.

Input member 18 and output member 17 in the axial space between themenclose a flange-like intermediate part 27 which simultaneouslyconstitutes the output member of the first damper stage 28 a and theinput member of the second damper stage 28 b. Input member 18, outputmember 17 and intermediate part 27 are equipped in an essentially knownmanner with windows for holding the energy-storing devices in the formof coil springs 29, 30 for the two damper stages 28 a, 28 b.

In the axial direction, input member 18 is connected to an intermediatepart 27, and the intermediate part 27 is connected to the output member17 by means of fasteners, here in the form of rivets 31, 32. The givenrange of play by which the parts can rotate relative to each other islimited by the rivets passing through elongated perforations 33, 34 thatare arranged along a circle on the input member 18 and on theintermediate part 27, forming stops limiting the extent of travel of therivets within the holes. As axial retainers for the rivets 31, 32,ring-shaped membranes 35, 36 are provided on the side of theperforations 33, 34. The axial spacing of the input member 18 from theintermediate part 27 and of the intermediate part 27 from the outputmember 17 is provided by energy-storing devices working in the axialdirection between the respective parts, represented in this embodimentby plate springs 44, 45.

The input member 18 at its interior perimeter has a profile shapedesigned to accommodate the energy-storing devices 30 so as to makeoptimum use of the available axial space, then turning into the axialdirection to form an axially oriented flange-like part 37 with a rim ofaxially directed teeth 21, where the input member 18 meets the exteriortoothed rim 39 of a friction-lining carrier 38 in a form-lockingengagement. The friction-lining carrier 38 is centered on a shoulder 41by means of lugs 40 bent into the axial direction towards the controlpiston 43 and is faced on both sides with friction linings 42 along itsouter perimeter. The friction-lining carrier 38 is interposed in theaxial direction between the control piston 43 and the annular disk 46.The latter is attached in a rotation-blocking connection to the housingshell 4, which in the respective area extends in the radial direction.Fastener means such as the impulse weld 48 of the present example areused for the connection. The annular disk 46 has cut-outs 47 distributedalong a circle that serve to promote circulation and cooling of thechamber 49 that is formed between the annular disk 46, the controlpiston 43 and the friction-lining carrier 38. The annular disk iscentered on the housing 2 by means of projections 57 arranged in acircle on the housing shell 4.

The axial displacement of the control piston 43 effects the slippingengagement, full engagement and disengagement of the lockup clutch 15.The control piston is actuated by the pressure differential in thechamber 50 that is located in the axial direction between the controlpiston 43 and the housing shell 4 and is supplied from a pressure pump(not shown) with a pressure medium entering through a channel 51 fromthe radially interior direction. To seal off the chamber 50, the controlpiston 43 is equipped along its inner and outer perimeter with sealingmeans 51 a, 52. Also, in order to improve guidance and to preventcanting and thereby jamming of the control piston, the latter is bentinto the axial direction at one perimeter, such as at the interiorperimeter in the present embodiment. To avoid slippage at the sealingmeans of the piston 43, the latter has a form-locking engagement withthe housing 2 through an axially oriented profile 54 which in thepresent embodiment consists of alternating ring segment-like recesses 53and projections 55 that are distributed over the circumference and areengaged by the complementary-shaped profile 56 of the housing shell 4.

The embodiment of FIG. 1 illustrates the function of thetorque-transmitting apparatus 1 as follows: When the lockup clutch isopen, the torque is transmitted by the pump 7 driving the turbine 10,assisted in known manner by the free-wheeling stator 11, through theconverter medium that fills the interior space 12 to the flange-likepart 22 from where the torque is introduced through an axial plug-inconnection formed by the engagement of toothed rims 20, 26 into theinput member 19 of the damper 13. When the lockup clutch 15 is closed,the torque-flow path runs through the form-locking engagement of themutually complementary profiles 54, 56 as well as through the annulardisk 46 that is connected to the housing 2. Through the frictionengagement of the control piston 43 and the annular disk 46 with thefriction linings 42, the torque is introduced into the friction-liningcarrier 38 which, by means of the axial plug-in connection with toothedrims 21, 40, transmits the torque to the input member 18. Continuingfrom the input member 18, the torque flow is smoothed in the damper 13by means of energy-storing devices 29, 30. The angular displacement ofboth damper stages 28 a, 28 b is bounded by limit stops 33, 34 andmatched to the characteristics and properties of the energy-storingdevices 29, 30. If a friction component is needed in the damper 13,i.e., in the damper stages 28 a, 28 b, the energy-storing devices 44, 45are designed independently of each other in such a manner that africtional engagement occurs for the first damper stage 28 a between thesecuring membranes 35, 36 and the input member 17 and/or for the seconddamper stage 28 b between the securing membranes 35, 36 and theintermediate part 27. The output member 17 of the damper 13 transmitsthe torque to the hub 14 representing the rotary output element of thetorque-transmitting apparatus 1, from where the torque is introducedinto the transmission shaft.

FIG. 2 shows an inventive torque-transmitting apparatus 101 of similarconfiguration as the torque-transmitting apparatus 1, but with amodified damper 113. The pump 107, stator 111, turbine 110, the overallconstruction, function and arrangement of the lockup clutch 115 areprovided in similar manner as has been described in connection with FIG.1.

The axial plug-in connection 178 in this embodiment is formed by theflange-like part 122, which is engaged without play in recesses 120 thatare distributed over the circumference of the input member 118. At itsinterior perimeter, the flange-like part 122 is connected to the shell123 of the turbine 10—by a weld 124 in the illustrated example.Subsequently, the flange-like part 122 conforms to the shape of theturbine shell at a radial distance, then turns into the axial directiontowards damper 113, where its rim of axially oriented teeth 126 engagesthe openings 120 of the input member 118. The toothed engagement occursat a radius inside the first damper stage 128 a and outside the seconddamper stage 128 b where the flange-like part 122 runs in the axialdirection and passes through elongated perforations 133 formed along acircle on the intermediate part 117 that is provided as output member ofthe first damper stage 128 a. Simultaneously, the flange-like part 122forms the limiting stops for the relative angular displacement betweenthe input member 118 and the intermediate part 117 within the angularrange that is delimited by the perforations 133. Thus, theenergy-storing devices 129 are bypassed in the case of large angulardisplacements and are protected against the possibility of harmfuleffects from high transient peaks in the torque flow. In thisembodiment, the energy-storing devices of the first, radially exteriordamper stage 128 a are formed in a known manner as arc-shaped springs129 that are accommodated and retained at their outside radius by achamber 118 b formed by the peripheral portion of the input member 118that is bent into the axial direction towards the turbine 110 and by anadditional lateral part 118 a enclosing the arc-shaped springs on theside facing the turbine 110. The chamber 118 b has provisions forapplying a force in the longitudinal direction of the springs in theshape of protrusions 118 c of the input member 118 and the lateral part118 a, and wear-protection shells may be interposed between the insidewall at the circumference of the chamber 118 b and the arc-shapedsprings 129. The intermediate part 127 representing the output member ofthe first damper stage 128 a is arranged between the input member 118and the lateral part 118 a (relative to the axial direction) and isequipped with radially arranged extremities 127 a along its outsideperimeter. A further radially extending flange-like part 127 b isconnected to the intermediate part 127 through fasteners such as therivets 131 shown in the present embodiment. With openings 130 a formedin a known manner, the flange-like part together with the intermediatepart 127 holds the energy-storing devices of the second damper stage 128b, in this embodiment represented by short, stiff helix springs 130distributed evenly along a circle. On the output side, the forceintroduction into the springs is accomplished with the output member 117that is interposed in the axial direction between the intermediate part127 and the flange-like part 127 b with openings 117 a corresponding tothe dimensions of the helix springs 130 that in the present embodimentconsist of sets of helix springs nested inside each other. At its outerperimeter, the output member 117 has extremities 117 b that are directedoutwards in the radial direction and engage openings 127 c in theflange-like part 127 b with play, thus allowing the intended range ofangular displacement for the second damper stage 128 b and providinglimit stops so that the second damper stage 128 b will be bypassed whenthe angular displacement of the extremities 117 b within the openings127 c has reached the limit.

By the interposition of energy-storing devices—in this case platesprings 144, 145—the respective input and output members 118, 127 of thefirst damper stage 128 a and 127, 117 of the second damper stage 128 bare spaced apart from each other, and through appropriate selection ofthe spring constants of the plate springs 144, 145, it is possible toachieve a desired amount of frictional torque at the friction surfaces144 a, 145 a.

In the present embodiment, the output member 117 and the output element114 with the interior toothed profile 116 for the torque-transmittingconnection to the transmission shaft (not shown) are formed as oneintegral part.

FIG. 3 illustrates an embodiment of a similar torque-transmittingapparatus 201 similar to the torque-transmitting apparatuses 1 and 101with a housing 202 that also contains a torque converter 203. The pump208 and the stator 211 are configured and arranged in the same manner ashas been described 11 in the context of FIG. 1.

The turbine 210 is spaced apart from the stator 211 by means of a rollerbearing 211 a and is connected to a hub 210 a by means of a weld 210 bmade, e.g., by impulse welding. The hub 210 a is centered on aprojection 214 b of the hub 214 extending axially towards the stator211. The hub 214 represents the output element of thetorque-transmitting apparatus 201 and has an interior toothed profile216 for a form-locking engagement with the outward-facing profile of atransmission shaft 272. For optimum use of space in the axial dimension,the projection 214 b surrounds the outside of the stationary sleeve 270that supports the stator 211 through a free-wheeling hub 271. In theaxial direction, the hub 210 a is held in place on the projection 214 bby a retaining ring 214 a. To limit the relative angular displacementbetween the turbine 210 and the hub 214, i.e., the working range of thedamper 213, the hub 210 a has axially directed bolts 273 engaged withthe required amount of rotational play in openings 274 of the hub 214,the latter representing at the same time the output member 217 of thedamper 213.

To accommodate the control piston 243 of the lockup clutch 215, afurther hub 275 is slidably supported on the transmission shaft androtatable relative to the hub 214 by means of a roller bearing 275 aretaining the hub 275 engaged with the housing 202. In first axially andthen radially outwards directed wall portions 202 a, 202 b of thehousing 202, axial and radial toothed profiles are, respectively,arranged for a form-locking engagement with complementary toothedprofiles 275 b on the hub 275. On the axially extending circumference ofthe hub 275, a seal 251 is provided for sealing the piston 243.

Located at a farther radius, the piston 243 has ridges 243 a running ina circle and projecting axially towards the friction-lining carriers238. When the piston 243 is displaced in the axial direction, the ridges243 a bear against the clutch disks 238 a and the friction-liningcarriers 238 that are faced on both sides with friction linings 242,resulting in slipping engagement, full engagement, and disengagement ofthe lockup clutch 215. The axial displacement of the piston 243 isenergized by the application of pressure differentials of a pressuremedium entering through a channel (not shown) into the tightly sealedchamber 250 that is formed by the piston 243 a where the sealinginterface between the outer circumference of the piston 243 and thehousing 204 is formed by a seal 252.

The clutch disks 238 a and an additional annular disk 277 that serves astake-up surface against the clutch force are at their exteriorcircumference engaged by a rotation-blocking toothed profile and securedaxially by a retaining ring 276 a in the exterior disk holder 276 thatis welded to the housing 204. The friction-lining carriers 238 are heldat their inside perimeter in the interior disk holder 218 e by arotation-blocking tooth profile. Consequently, when there is frictionengagement between the clutch disks 238 a and the friction linings 242,a torque-locked connection is established between the housing 202 andthe interior disk holder 218 e, whereby the latter imparts the appliedtorque to the input member 218. For this purpose, the inner disk holderis shaped as a ring of approximately rectangular cross-sectionalprofile. The portion of the disk holder that is running in the axialdirection towards the housing 204 supports the friction-lining carriers238, while the second portion, extending outwards in the radialdirection, is attached to a radially directed portion-of the inputmember 218 in a non-rotatable connection by means of fasteners such asthe rivets 231 that are arranged along a circle in the illustratedexample.

As has been described, the input member 218 of the damper 213 takes upthe applied torque in the case where the lockup clutch 215 is closed orat least partially engaged. When the lockup clutch 215 is open as welland when it is slipping, the torque (or a portion of the torque when thelockup clutch 215 is slipping) is passed on from the turbine 210 throughan axial plug-in connection 278 to the input member 218 in the samemanner as was described in the context of FIG. 1, but using thearrangement and functional concept of FIG. 2, where the input member 218together with the lateral part 218 a forms a chamber 218 b toaccommodate the arc-shaped springs 229 with the wear-protection shells218 d inserted at the contact surfaces. In order to form the axialplug-in connection 278, the axially directed portion of the input member218 is extended at the outer circumference towards the turbine in such amanner that its axially directed toothed rim 226 can engage theoutward-pointing toothed rim 220 of the radially directed flange-likepart 222 that is attached to the turbine.

Input member 218 and lateral part 218 a are connected by means offasteners represented in the present embodiment by the rivets 231 withspacer bolts 231 a to hold them at a fixed distance from each other.Arranged in the space extending in the axial direction between inputmember 218 and lateral part 218 a is the intermediate part 227 in theshape of a disk-shaped part 227 serving as output member of the firstdamper stage 228 a and as input member of the second damper stage 228 b.The detail configuration of the disk-shaped part 227 is illustrated in apartial view in FIG. 4.

The FIGS. 3 and 4 show a disk-shaped part 227 with radially directedextremities 227 a arranged at the exterior circumference and serving asforce-introduction elements for the arc-shaped springs (FIG. 3).Distributed along a circle of smaller radius in the disk-shaped part areelongated openings 233 through which the rivets 231 pass, permittingrelative rotation between the input member and the output member of thefirst damper stage 228 a within a limited angular range. As soon as therivets 231 reach the borders of the cutouts 233, the first damper stage228 a is bypassed and the applied torque is transmitted through thecontact points between the rivets 231 and the cutouts 233, whereby thearc-shaped springs are protected against greater amounts of torque andangular displacement. The rest position of the rivets 231 in theillustrated embodiment is not centered within the cutouts 233 (seen inthe circumferential direction), meaning that the range of angulardisplacement is not equal in both directions but is smaller in the“push” direction than in the “pull” direction. In an inventiveembodiment not shown in the drawing, the rivets 231 can be in directcontact with the border 233 a of the elongated openings 233 so that thisdamper stage is being bypassed immediately in the push direction withoutan angular displacement, thus providing a damper with one active stagein the push direction and two active stages in the pull direction.Distributed over another yet smaller circle in the disk-shaped part arefurther openings 227 b to hold the energy-storing devices in the form ofshort helix springs 230 nested inside each other (FIG. 3). At theirouter radius, the openings 227 b have flaps 230 a that are bent towardsthe lockup clutch 215 to secure the helix springs 230 in the axialdirection. By means of the rivets 232 passing through holes 227 c (FIG.4) distributed along a circle of intermediate radius between theopenings 233, 227 b, the disk-shaped part 227 is connected to a furtherflange-like part (227 b) that has openings with flaps (227 c) bentaxially towards the turbine to accommodate the helix springs 230. Theflange-like part (227 c) is formed into the shape of a cup extending inthe axial direction to provide space in the axial dimension between theintermediate part 227 and the flange-like part (227 b) to accommodatethe hub 214. The hub 214 is extended radially into a disk shape to serveas output member 217 of the damper 213 and thus of the second damperstage 228 b. To provide space for and couple a force to the helix spring230, the output member 217 has openings 217 a distributed along a circleso that the hub 217 is rotatable relative to the intermediate part 227against the restoring force of the helix springs 230. This produces thedamping effect of the second damper stage 228 b wherein the range ofangular displacement is limited by the play of the bolts 273 in theopenings 274.

The input member 218 and the output member 227 of the first damper stage228 a as well as the input member 227 and the output member 217 of thesecond damper stage 228 b are elastically clamped against each other bythe action of the interposed plate springs 244, 245. Thus, with anappropriate selection of the spring characteristic, a friction effect ofa desired magnitude can be generated between the respective input andoutput members 218, 227 and 227, 217 at the friction surfaces 244 a, 245a, where the friction surface 245 a is provided by a series ofprojections distributed along a circle on the lateral part 218 a.

FIG. 5 illustrates an embodiment of a damper 313 in single-stageconfiguration. The torque to be transmitted is introduced into thedamper 313 through the two lateral parts 318 a, 318 b that form theinput member 318. The contributions to the torque coming from the lockupclutch 315 are introduced into the damper 313 through the toothed rim321 of the lateral part 318 a of the input member 318. The contributionsto the torque coming from the turbine 310 are introduced through theinventive plug-in connection 378 into the input member 318, representedby its lateral part 318 b. In addition, a disk-shaped part 322 isconnected by means of rivets 332 with the turbine 310, with the hub 314(that represents the output element and is connected to the transmissionshaft 372 through a toothed profile 316) and with the output member 317.The spacer bolts 332 a are provided to allow an angular displacement ofthe output member 317 relative to the turbine 310, hub 314 and lateralpart 322 within a range that is delimited by the borders of elongatedopenings 334. The disk-shaped part 322 is engaged in a toothed exteriorprofile 314 a of the hub 314 without play. At its outer circumference,the disk-shaped part 322 has an exterior toothed rim 326 that forms theplay-free plug-in connection 378. Also engaged in the toothed exteriorprofile 314 a of the hub 314 is the output member 317 of the damper 313,which has a toothed inner perimeter 317 a with an amount of play betweenthe opposing tooth flanks that determines the range of relative angulardisplacement between the input member and the output member inopposition to the restoring torque of the energy-storing devices 329. Itshould be noted, however, that the openings 334 and the elongatedfurther openings 333 that are located farther out in the radialdirection on the output member 317 will permit a larger amount ofangular displacement. Nevertheless, it is conceivable in principle thatthe maximum amount of angular displacement is determined by any one ofthe three elements 317 a, 333, 334.

The energy-storing devices 329 have the shape of arc-shaped springs 329.The configuration of the chamber 318 c that accommodates the arc-shapedsprings 329 as well as the arrangement and function of theforce-introducing elements have been described previously in the contextof FIGS. 2 and 3.

The lateral parts 318 a, 318 b are connected in the axial direction bymeans of rivets 331 and spacer bolts 331 a and are held at a suitabledistance from each other to allow the output member 317 to be arrangedwithin the axial space between them. Interposed between the lateral part318 a and the output member 317 is a plate spring whose axial thrustdetermines the intensity of the frictional engagement between the outputmember 317 and a circular ridge 318 d formed on the lateral part 318 b.

FIG. 6 illustrates a further embodiment of a two-stage damper 413 of thekind that was described in the context of FIG. 3, except for thefollowing distinguishing features: The turbine 410 is supported in amanner permitting relative rotation directly by the hub 414 that formsthe output element; it is centered on a shoulder 414 b provided for thispurpose and secured in the axial direction by a retaining ring. Thus thehub 210 a shown in FIG. 3 can be omitted. The bolts 473 delimiting themaximum angular displacement between output member 417 and output member418 are distributed along a circle and configured to protrude directlyfrom the hub 414 into the axial direction, engaging the input member 418through elongated openings 474 that provide the limiting stops. For theform-locking engagement with the lockup clutch (not shown), a ring 418 eof rectangular profile is attached to the input member 418 by means ofrivets (231) that are arranged along a circle. The radially directedportion of the ring 418 e is riveted to the input member 418, while theaxially directed portion provides the form-locking engagement with thelockup clutch by means of an axially directed profile.

FIG. 7 illustrates a further inventive embodiment of atorque-transmitting apparatus 501 with a single-stage damper 513 and amodified lockup clutch 515.

The control piston 543 of the lockup clutch 515, which is axiallydisplaceable, sealed and centered on the transmission shaft 572, carriesa friction lining 542 along its radially exterior peripheral area on theside that is facing the friction surface 504 a on the housing 504. Whenthe clutch is closed or slipping, the friction lining 542 isfrictionally engaged with the friction surface 504 a of the housing 504and thereby introduces the torque to the input member 518 consisting oflateral parts 518 a and 518 b.

At a point between the housing 504 and the piston 543, converter fluidis suctioned off through an outlet channel (not shown), whereby an underpressure is generated relative to the converter chamber 512, resultingin an axial displacement of the piston 543, thus providing thecapability of controlling the slipping engagement, closing and openingof the lockup clutch 515. The friction engagement between the frictionsurface 504 a and the friction linings 542 can be controlled so that thelockup clutch 515 slips while the friction linings 542 are being cooledby the passing flow of the converter medium. However, it is alsopossible to engage the lockup clutch without slippage. The frictionsurface 504 a and the control piston 543 are cone-shaped in the vicinityof the friction engagement, so that the closure and friction engagementof the lockup clutch are enhanced by the effect of the centrifugalforce.

In a circular area of smaller radius than the friction linings 542, thepiston 543 has protuberances 543 a projecting in the axial directiontowards the input member 518 where the piston 543 is connected to thelateral parts 518 a and 518 b by means of bolts 543 b in a mannerpermitting axial but blocking rotational movement of the piston inrelation to the input member 518. The two lateral parts 518 a, 518 b areriveted together at their outer circumference (rivets not shown), whilethe bolts 543 b are inserted into cutouts 518 c on the lateral parts 518a, 518 b that are open at the outer perimeter and thereby permit anaxial play between the piston 543 and the input member 518. The purposeis to prevent negative effects on the axial mobility of the piston 543from stresses that occur during the engagement and disengagement of thelockup clutch between the piston 543 and the already torque-loaded inputmember 518.

The torque introduction through the turbine 510 occurs by means of aturbine hub 510 a that is centered on the hub 514 representing theoutput element. The turbine hub 510 a is fixedly attached to the turbine510 and has axially directed projections 573 distributed along its outerperimeter that are engaged without play—in order to avoid a one-sidedintroduction of torque—in openings of both lateral parts 518 a, 518,thereby forming the inventive plug-in connection 578 between the turbine510 and the input member 518.

The disk-shaped output member 517 that is formed out of the hub 514,together with the input member 518 and the energy-storing devices in theform of nested helix springs 530, represent an essentially known damperdevice 513. A series of openings (574) is distributed along a circle onthe output member 517. The projections 573 of the turbine hub 510 a passthrough the openings (574) and stop the relative angular displacementbetween the input and output members 518, 517 against the restoringtorque of the energy-storing devices 530 as soon as the projections 573run against the borders of the openings (574).

FIG. 8 illustrates a further possible configuration of a damper device613 of the inventive torque-transmitting apparatus. In contrast to thedamper devices described above, the hub 614 is composed of two hubcomponents 614 a, 614 b. The hub component 614 a is mounted on thetransmission shaft 672 in play-free and rotation-blocking connection.The hub component 614 b is supported and aligned on a shoulder 614 darranged axially on the hub component 614 a on the side towards thetransmission. The hub component 614 b is secured axially by means of aretaining ring 614 c. The turbine 610 is firmly connected with the hubcomponent 614 b, e.g., by welding or keying. To form a meshingengagement with play between the first and second hub components 614 a,614 b, the second hub component 614 b has axially directed projections673 distributed along its circumference, which engage openings 674 ofthe hub component 614 a. The dimension of the openings 674 in thecircumferential direction is such that the projections 673 in concertwith the openings 674 permit a desired amount of relative angulardisplacement between the turbine 610 and the hub component 614 a, withthe damper 613 being interposed between them. The output member 617 ofthe damper device 613 is arranged axially between the two hub components614 a, 614 b, centered on the hub component 614 a and rotationally tiedto it by means of the keyed connection 614 e. The output member 617rests against the hub component 614 a along a series of projectionsdistributed on a circle or a circular ridge 614 f protruding in theaxial direction. At locations that correspond to the openings 674, theflange-like output member 617 of the damper device 613 has openings 675that are engaged by the projections 673 of the hub component 614 b. Itis advantageous if the openings 675 are wider in the circumferentialdirection than the openings 674, so that the limits of angular play aredetermined by the openings 674. This prevents the torque from enteringthe hub component 614 a through the keyed connection 614 e, so that thelatter does not have to be dimensioned for the torque loads that wouldoccur in that case. The function of the further components of the damperdevice 613 is otherwise comparable with the other damper devices thathave been described above.

The FIGS. 9-12 show partial sectional views of embodiments of dampers713 a-d that are similar to the damper 213 of FIG. 3. The dampers 713a-d differ from the damper 213 and in part among each other in thedifferent configuration of the input member 718 a-d and the outputmember 717.

In contrast to the hub 214 and the output member 217 being configuredtogether as one piece as in FIG. 3, the dampers 713 a-d of FIGS. 9-12have output members 717 and hubs 714 in two-piece configuration, inwhich the output members 717 are sheet metal stampings attached to andcentered on the hub 714 in a rotation-blocking connection, e.g., byshrink-fitting. To accommodate the energy-storing devices of the seconddamper stage, the disk-shaped output members 717 have window-shapedopenings 717 a distributed along a circle. The disk-shaped outputmembers 717 limit the angular displacement of the second damper stage bymeans of radially directed extremities 717 b distributed along thecircumference, which are engaged with the required amount of angularplay in corresponding openings of the disk-shaped part 727 b that servesas input member of the second damper stage.

In the dampers 713 a, 713 c of the FIGS. 9 and 11, respectively, theinput members 718 a, 718 c of the damper that transmit an applied torquefrom the converter lockup clutch 715 and/or from the turbine 710 to thedamper 713 a, 713 c are of single-piece configuration, i.e., they haveat their inner circumference an axially directed extension 778 a, 778 cwith a profile 780 a, 780 b for a rotation-blocking engagement of thedisks 742 a, 742 b. The profile 780 a (FIG. 9) is impressed into theexterior circumference of the extension 778 a, while the profile 780 c(FIG. 11) is formed by axially oriented openings distributed over thecircumference of the extension 778 c for a rotation-blocking engagementof the correspondingly profiled disks 742 b.

The dampers 713 b, 713 d of FIGS. 10, 12 have an input member 718 b, 718d firmly connected, preferably riveted as shown here, to the flange-likepart 778 b, 778 d of L-shaped cross-section. The flange-like parts 778b, 778 d have profiles 780 b, 780 d corresponding to the extensions 778a, 778 c of FIGS. 9, 11 for a rotation-blocking connection with thedisks 742 a, 742 b of the converter lockup clutch 715.

FIG. 13 represents a cross-sectional view of an embodiment of atorque-transmitting apparatus 801. Its damper 813, shown here in atwo-stage configuration working in serial mode, is at its outerperimeter solidly connected and thereby axially constrained to theturbine 810. At its inner perimeter, the damper 813 has an axiallydisplaceable but non-rotatable connection to the hub 814.

The damper 813 is attached to the turbine shell 823 by means of a weldseam or spot welds 822 a using essentially known welding methods suchas, e.g., induction welding, laser welding, impulse welding, or othersuitable welding methods. It is to be understood that any otherfastening method such as riveting, as well as self-locking connections,could also be used advantageously. In the illustrated embodiment, aconnector flange 822—or alternatively an arrangement of connector lugsin the shape of circular segments distributed over a circumference—isattached, e.g., welded, to the turbine shell 823. The axially directedextension 820 of the input member 819 is slipped over the connectorflange 822 or the connector lugs and then attached as described above.It can be advantageous if in the attachment process the connector flange822 is centered on the turbine and the input member 819 is centered onthe connector flange.

Additionally or alternatively, it can be of advantage if the seconddamper stage is centered on the first damper stage in order to preventdisplacement of the two damper stages relative to each other. Thus it ispossible to accomplish the centering through a configuration in the area888 where a component 818 a of the input member of the first damperstage overlaps radially with a component 827 b of the output member ofthe first damper stage (which is also the input member of the seconddamper stage), allowing the two damper stages to be positioned relativeto each other.

The output member 817 of the damper 813 is connected to the hub 814through an inward-facing toothed profile that engages an exteriortoothed profile of the hub 814, allowing axial but preventing angularrelative displacement, so that stresses between the outer attachment 822a and the interior connection of the damper 813 are prevented.

The turbine 810 is supported through a turbine hub 873 on an axiallyprojecting shoulder 814 b of the hub 814. The turbine hub 873 haslimited rotational play relative to the hub 14 and is axially secured bya retaining ring 814 c. The angular displacement of the turbine 810relative to the hub 814, i.e., the working range of the damper 813, islimited by axially directed projections 873 a distributed along a circleon the turbine hub 873 that are engaged with angular play in theexterior toothed profile 814 a of the hub 814. It is to be understoodthat the toothed interior rim 817 a of the output member 817 and theprojections 873 a of the turbine hub 873 do not have to be arranged sideby side as shown in FIG. 13 but may instead be one above the other forthe benefit of minimizing the overall axial dimensions, in which case itis advantageous if the projections 873 a are arranged inside the radiusof the toothed rim 817 a.

FIG. 14 illustrates a damper 913 that has been modified in comparison tothe damper 813 of FIG. 13 in that the disk-shaped input member 927 b ofthe second damper stage is shaped at its interior periphery in such amanner that by means of an axially directed extension 927 c, the damper913 can be centered on the exterior toothed profile 914 a of the hub914. By means of the centering feature 988, the first damper stage 928 acan be centered on the second damper stage 928 b. The axially androtationally fixed connection of the input member 918 to the turbineshell (not shown) can thus be made with a tighter tolerance, e.g.,according to the embodiment of FIG. 15.

An alternative to the solution shown in FIG. 13 for attaching the damper813 to the turbine shell 823 by means of a connector flange 822 isillustrated in the detail view of FIG. 15. The rim 920 a of the axiallydirected extension 920 of the input member 918 of the damper is adaptedto the shape of the turbine shell 923 of the turbine 910 and attachedalong a circle by a continuous weld seam or individual spot welds 922 a.

FIG. 16 shows a partial section of a further embodiment of atorque-transmitting apparatus device 1001 that is similar to theembodiment of FIG. 13. Modifications that deviate from the embodiment ofFIG. 13 are in the hub area, including a hub 1014 that is also shown inthe detail view of FIG. 17.

As may be seen in FIGS. 16 and 17, the two form-locking connections forthe transmission of the torque from the damper 1013 through its outputmember 1017, and from the turbine 1010 through the turbine hub 1073, tothe hub 1014 and from there through the toothed-profile connection 1016to the transmission shaft are spatially separated from each other. Atits exterior circumference, the hub 1014 has an outward-facing profile,such as the illustrated toothed rim 1014 a, that meets the complementaryinterior profile 1017 a of the output member 1017 in a form-fittingengagement that is preferably free of play and permits axialdisplacement. Inside of the toothed rim of the hub 1014 arewindow-shaped openings 1014 b distributed along a circle, shown here inan arrangement of four, but arrangements of two or six openings may alsobe advantageous. The axially directed projections 1073 a of the turbinehub 1073 pass through the window-shaped openings 1014 b and establish apositive engagement with a maximum play angle a-b (amounting to, e.g.,10° to 70° in the case where four openings are used), between the hub1014 and the turbine hub 1073 that is rotatable and axially constrainedon the hub 1014, whereby the maximum angular working range a-b of thedamper 1013 is being determined in an advantageous manner. For reasonsof structural integrity, the openings 1014 b are widened and rounded inboth radial directions in the vicinity 1014 c of the contact areas forthe projections 1073 a. The toothed rim profile 1014 a is interrupted inthe circumference segments 1014 d adjacent to the radial enlargements1014 c.

The axial fixation of the damper 1013 is modified slightly in comparisonto the embodiment 801 of FIG. 13 in that, unlike the connector flange822 of FIG. 13, the connector flange 1022 is not fitted to the radialshape of the turbine shell 1023 and then continued in an outward radialdirection. Rather, the connector flange 1022 has a planar, radiallyoutward-directed shape with a taper 1022 b at the contact surface to theturbine shell 1023 and is connected to the latter preferably at itsinner perimeter through weld seams or a string of evenly distributedspot welds 1022 c, 1022 d. The connection 1022 a between the connectorflange 1022 and the input member 1018 of the damper 1013 is made in thesame manner as in the embodiment 801 shown in FIG. 13.

The function of the damper 1013, likewise, is similar to the dampers213, 813 of the FIGS. 3 and 13, respectively, where it should be notedthat the dampers shown in the illustrated sample embodiments areserially configured two-stage dampers. However, in applying theinvention it may also be of advantage to provide a parallel mode ofoperation for dampers with two or more stages. It may further bebeneficial, to provide individual limits for the angular displacement ofeach damper stage, as in the present case for the damper stages 1013 a,1013 b, in addition to the delimitation of the relative angulardisplacement of the entire damper 1013 by means of the projections 1073a in combination with the openings 1014 b. For this purpose, the firstdamper stage 1013 a as well as its output member 1077 have window-shapedopenings 1033 distributed along a circle that are engaged with angularplay by the rivet bolts 1031 that connect the two input members 1018,1018 a. In case of a rotation of the input members 1018, 1018 a relativeto the output member 1077 of the first damper stage 1013 a, when therange of play has been used up, the rivet bolts will act as stops andthereby cause the damper stage 1013 a to be bypassed.

In analogous manner, the rivet bolts 1032 connecting the input member1077 of the second damper stage 1013 b (which also represents the outputmember of the first damper stage 1013 a) with the disk-shaped part 1078restrict the angular displacement of the second damper stage 1013 b asthey perform the function of rotation-limiting stops for the radiallydirected extremities 1017 e on the circumference of the output member1017, whereby the range of relative rotation between the input members1077, 1078 and the output member 1017 is determined by the amount ofplay between the rivet bolts 1032 and the extremities 1017 e.Preferably, the ranges between stops for the first and second damperstages 1013 a, 1013 b as well as for the entire damper are coordinatedin such a manner that the individual damper stages 1013 a, 1013 b reachtheir stops at a point before the limit angle of the entire damper hasbeen attained by the projections 1073 a reaching the end of their play.For specific applications it may further be advantageous if the firstdamper stage is stopped before the second stage or vice versa.

It must be understood that features and functions described forindividual embodiments of the torque-transmitting apparatus can also beadvantageously applied in the rest of the embodiments, regardless ofwhether or not they are being shown, even if these features andfunctions have not been described in detail in the context of therespective embodiment and that, therefore, such features and functionsare considered to be included in the coverage of all embodiments towhich they are applicable.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic and specific aspects of theaforedescribed contribution to the art and, therefore, such adaptationsshould and are intended to be comprehended within the meaning and rangeof equivalence of the appended claims.

What is claimed is:
 1. Apparatus for transmitting torque comprising ahydrokinetic torque converter with at least one housing connectable to adriving shaft of a prime mover, the housing containing and impartingtorque to at least one pump and also containing a rotary turbineconnectable to and arranged to drive an input shaft of a power train,and with further at least one damper arranged in a power flow pathbetween the turbine and a rotary output element of the apparatus, thedamper having an input member constrained to rotate with the turbine andan output member connected to the rotary output element, the damperhaving a radially outer connection to the turbine, the input member andthe output member being rotatable relative to each other at leastagainst the opposition of a restoring force of energy-storing devicesarranged between them, wherein the input member is connected to anengageable and disengageable lockup clutch.
 2. The apparatus accordingto claim 1, said turbine including a first hub axially restrained androtatable on a second hub surrounding the input shaft, the damper havinga radially inner, rotation-locked connection to the second hub with oneof the radially outer connection and the radially inner connection beingrestrained from axial movement relative to the turbine and the secondhub, respectively.
 3. The apparatus according to claim 1, wherein thetorque converter further includes a stator interposed between the pumpand the turbine.
 4. The apparatus according to claim 1, wherein theinput shaft of the power train is a transmission shaft.
 5. The apparatusaccording to claim 1, wherein the lockup clutch includes means forestablishing a force-locking connection between the housing and thedamper.
 6. The apparatus according to claim 1, wherein the lockup clutchhas at least one friction-lining carrier with at least one frictionlining.
 7. The apparatus according to claim 1, wherein the lockup clutchis a disk clutch.
 8. The apparatus according to claim 1, wherein thelockup clutch is controlled by an axially moveable control piston. 9.The apparatus according to claim 8, wherein the control piston in anengaged state of the lockup clutch forms a plenum chamber with anessentially tight separation from a chamber formed by the housing. 10.The apparatus according to claim 8, wherein the control piston iscentered on, axially movable in relation to, and sealed against thetransmission shaft.
 11. The apparatus according to claim 8, wherein thecontrol piston is centered on, axially movable in relation to, andsealed against a hub that supports the housing and surrounds thetransmission shaft.
 12. The apparatus according to claim 8, wherein thecontrol piston is axially movable relative to the housing and has anoutside perimeter along which the control piston is sealed against thehousing.
 13. The apparatus according to claim 8, wherein the controlpiston constitutes the lockup clutch.
 14. The apparatus according toclaim 1, wherein a component of the lockup clutch is connected to theinput member of the damper.
 15. The apparatus according to claim 1,wherein the damper comprises at least two damper stages.
 16. Theapparatus according to claim 15, wherein the two damper stages areconfigured to operate in series.
 17. The apparatus according to claim15, wherein the two damper stages comprise at least one common disk-likepart.
 18. The apparatus according to claim 15, wherein each damper stagehas an input member and an output member and the input member and outputmember of each damper stage are rotatable relative to each other throughequal angles.
 19. The apparatus according to claim 15, wherein eachdamper stage has an input and an output members and the input member andoutput members of each damper stage are rotatable relative to each otherwithin different angles.
 20. The apparatus according to claim 15,wherein the damper is arranged to transmit torque both in a pulldirection and a push direction, and at least one damper stage isinactive in one of said directions.
 21. The apparatus according to claim20, wherein the damper stage that is inactive in one of the directionscomprises a bypass for connecting the input member with the outputmember when the damper stage is in an inactive mode.
 22. The apparatusaccording to claim 21, wherein the bypass is effected by the mutualengagement of rotation-limiting stops provided on the input member andthe output member.
 23. The apparatus according to claim 1, wherein eachof the input and output members of the damper comprises a lateral part.24. The apparatus according to claim 1, wherein the input membercomprises two lateral parts and the output member comprises aflange-like part interposed between the two lateral parts.
 25. Theapparatus according to claim 1, wherein the input member and the outputmember are connected by engagement means evenly distributed along acircle, said engagement means comprising in one of said members a set ofelongated holes with a dimension corresponding at least to a maximumangle of relative rotation between said members, and comprising in theother of said members a set of matching connector means engaging saidelongated holes, whereby the input member and the output member areallowed to rotate relative to each other.
 26. The apparatus according toclaim 24, wherein the flange-like part includes by a disk-like partextending radially outwards from a hub constituting the rotary outputelement.
 27. The apparatus according to claim 24, wherein the lateralparts are centered on a hub constituting the rotary output element. 28.The apparatus according to claim 24, wherein the flange-like part iscentered on a hub constituting the rotary output element.
 29. Theapparatus according to claim 24, wherein at least one of the lateralparts defines a chamber wherein the energy-storing devices are heldagainst movement in the radial direction.
 30. The apparatus according toclaim 1, wherein at least one force-introducing element for theenergy-storing device is provided on each of the input and outputmembers.
 31. The apparatus according to claim 1, wherein said energystoring devices comprises compression coil springs.
 32. The apparatusaccording to claim 15, wherein compression coil springs with differentspring-rate characteristics are used as the energy-storing devices forthe two damper stages.
 33. The apparatus according to claim 15, whereinat least one arcuately pre-shaped compression coil spring extendingapproximately along an outer circumference of the damper is used as theenergy-storing device for one of said damper stage.
 34. The apparatusaccording to claim 1, wherein the input member and the output member arerotatable relative to each other within an angle determined by at leastone rotation-limiting stop.
 35. The apparatus according to claim 34,wherein the rotation limiting stop includes means for uncoupling theenergy-storing devices of the damper from the power flow.
 36. Theapparatus according to claim 25, wherein at least one rotation-limitingstop is constituted by at least one connector means extendable into atleast one end portion of at least one of the elongated holes.
 37. Theapparatus according to claim 34, wherein the rotation-limiting stopincludes a flange-like part arranged on the rotary output element, atleast one extremity of the flange-like part being axially engaged in atleast one opening formed along a perimeter of the input member, theopening having an angular width that determines a range of rotary play.38. The apparatus according to claim 34, wherein an axially directedflange-like part forming the rotation-limiting stop is attached to theturbine.
 39. The apparatus according to claim 2, wherein an axiallydirected flange-like part forming a rotation-limiting stop is formed outof the first hub.
 40. The apparatus according to claim 34, wherein therotation-limiting stop is formed by the engagement of an outward-facingtoothed profile of the rotary output element and an inward-facingtoothed profile of a flange-like part forming the input element, theengagement having an angular play between tooth flanks.
 41. Theapparatus according to claim 1, wherein the input member has an axiallyand rotationally fixed connection to the turbine wheel, and the outputmember is rotationally fixed and axially moveable on a hub that isrotationally tied to the rotary output element.
 42. The apparatusaccording to claim 1, wherein the input member is welded to the turbinewheel.
 43. The apparatus according to claim 42, wherein the input memberis welded to the turbine wheel by a process selected from the group thatconsists of laser welding, impulse welding, MIG (Metal/Inert Gas)welding, friction welding, and resistance welding.
 44. The apparatusaccording to claim 41, wherein the output member has an inward-facingprofile in form-locking engagement with an outward-facing profile of thehub.
 45. The apparatus according to claim 2, wherein an outward-facingprofile of the second hub is engaged by a profile of the first hub, theengagement having at least as much angular play as the damper.
 46. Theapparatus according to claim 2, wherein the second hub has window-shapedopenings distributed evenly along a perimeter and serving for anengagement with the first hub with angular play.
 47. The apparatusaccording to claim 2, wherein the damper is centered on the second hubby means of a disk-like part serving to hold the energy-storing devices.